While we have double the dogs we usually have, we thought it'd be interesting to do a little dog food comparison & see which dog food is preferred. Our dogs (which we'll call the White Team since they're both white) normally eat Canidae and the visiting dogs (which we'll call the Black Team since they're both black) normally eat Blue Buffalo. Both are high-quality dry dog foods that are similar enough that we (and the owners of Dex & Sam) agreed that it'd be ok to have a bowl of each brand of food available to all four dogs.
First Day: All 4 dogs ate like there was no tomorrow! Seriously, they ate twice as much as they usually do. The White team (aka our dogs) ate Blue Buffalo almost exclusively. Black team (aka the visitors) ate Canidae almost exclusively. Both bowls were almost completely empty at the end of the day. While the dogs were extremely active, I think part of the encreased eating was due to having something new since each chose the food he/she didn't normally receive.
Second Day: Food consumption returned to normal. All 4 dogs returned to eating their own brand, and at the end of the day both bowls were still half full. The dogs were not as active today since the excitement of having each other around had abated. Funny that the "new" wore off this fast, both with having new companions & with having different food. All 4 are happy & content, playing and napping.